[nrf fromlist] drivers: i2c: add DMM to i2c_nrfx_twim

Added DMM buffer preparation to I2C TWIM driver.
Adds little impact as buffer content is already copied
into message buffer which is places in proper memory for
optimized transfer.

Upstream PR #: 93083

Signed-off-by: Michał Stasiak <[email protected]>

Author: mstasiaknordic

drivers/i2c/i2c_nrfx_twim.c

@@ -14,6 +14,7 @@
 #include <nrfx_twim.h>
 #include <zephyr/sys/util.h>
 #include <zephyr/linker/devicetree_regions.h>
+#include <dmm.h>
 
 #include <zephyr/logging/log.h>
 #include <zephyr/irq.h>
@@ -33,6 +34,7 @@ struct i2c_nrfx_twim_data {
 	struct k_sem transfer_sync;
 	struct k_sem completion_sync;
 	volatile int res;
+	uint8_t *buf_ptr;
 };
 
 int i2c_nrfx_twim_exclusive_access_acquire(const struct device *dev, k_timeout_t timeout)
@@ -70,6 +72,7 @@ static int i2c_nrfx_twim_transfer(const struct device *dev,
 	uint16_t msg_buf_size = dev_config->msg_buf_size;
 	uint8_t *buf;
 	uint16_t buf_len;
+	uint8_t *dma_buf;
 
 	(void)i2c_nrfx_twim_exclusive_access_acquire(dev, K_FOREVER);
 
@@ -134,7 +137,23 @@ static int i2c_nrfx_twim_transfer(const struct device *dev,
 			buf = msg_buf;
 			buf_len = msg_buf_used;
 		}
-		ret = i2c_nrfx_twim_msg_transfer(dev, msgs[i].flags, buf, buf_len, addr);
+
+		if (msgs[i].flags & I2C_MSG_READ) {
+			ret = dmm_buffer_in_prepare(dev_config->mem_reg, buf, buf_len,
+							(void **)&dma_buf);
+		} else {
+			ret = dmm_buffer_out_prepare(dev_config->mem_reg, buf, buf_len,
+							(void **)&dma_buf);
+		}
+
+		if (ret < 0) {
+			LOG_ERR("Failed to prepare buffer: %d", ret);
+			return ret;
+		}
+
+		dev_data->buf_ptr = buf;
+
+		ret = i2c_nrfx_twim_msg_transfer(dev, msgs[i].flags, dma_buf, buf_len, addr);
 		if (ret < 0) {
 			break;
 		}
@@ -196,6 +215,16 @@ static void event_handler(nrfx_twim_event_t const *p_event, void *p_context)
 {
 	const struct device *dev = p_context;
 	struct i2c_nrfx_twim_data *dev_data = dev->data;
+	const struct i2c_nrfx_twim_common_config *config = dev->config;
+
+	if (p_event->xfer_desc.type == NRFX_TWIM_XFER_TX) {
+		dmm_buffer_out_release(config->mem_reg,
+			(void **)&p_event->xfer_desc.p_primary_buf);
+	} else {
+		dmm_buffer_in_release(config->mem_reg, dev_data->buf_ptr,
+			p_event->xfer_desc.primary_length,
+			p_event->xfer_desc.p_primary_buf);
+	}
 
 	switch (p_event->type) {
 	case NRFX_TWIM_EVT_DONE:
@@ -275,6 +304,7 @@ static DEVICE_API(i2c, i2c_nrfx_twim_driver_api) = {
 		IF_ENABLED(USES_MSG_BUF(inst),						      \
 			(.msg_buf = twim_##inst##_msg_buf,))				      \
 		.max_transfer_size = MAX_TRANSFER_SIZE(inst),				      \
+		.mem_reg = DMM_DEV_TO_REG(DT_DRV_INST(inst)),				      \
 	};										      \
 	PM_DEVICE_DT_INST_DEFINE(inst, twim_nrfx_pm_action, I2C_PM_ISR_SAFE(inst));	      \
 	I2C_DEVICE_DT_INST_DEINIT_DEFINE(inst, i2c_nrfx_twim_init, i2c_nrfx_twim_deinit,      \

drivers/i2c/i2c_nrfx_twim_common.h

@@ -75,6 +75,7 @@ struct i2c_nrfx_twim_common_config {
 	uint8_t *msg_buf;
 	uint16_t max_transfer_size;
 	nrfx_twim_t *twim;
+	void *mem_reg;
 };
 
 int i2c_nrfx_twim_common_init(const struct device *dev);